2008 United States presidential election in Colorado

The 2008 United States presidential election in Colorado took place on November 4, 2008, as a part of the 2008 United States presidential election throughout all 50 states and the District of Columbia. Voters chose nine representatives, or electors to the Electoral College, who voted for president and vice president.

Colorado was won by Democratic nominee Barack Obama by a margin of victory of 8.95%. Obama took 53.66% of the vote to McCain's 44.71%. The state was heavily targeted by both campaigns, although, prior to the election, all 17 news organizations actually considered this a state Obama would win, or otherwise considered as a likely blue state. While George W. Bush narrowly carried the state in 2004, Colorado ultimately flipped to Obama. This was the first time since 1992 in which the state was won by a Democrat in a presidential election, as well as the first of currently four consecutive times since 1944 in which it voted differently than Montana, another rocky mountain state.

Key to Obama's victory was Democratic dominance in the Denver area, sweeping not just the city but also the heavily populated suburban counties around Denver, particularly Adams, Arapahoe, and Jefferson counties, as well as winning Larimer County, home to Fort Collins. Obama also took over 70% of the vote in Boulder County, home to Boulder. McCain's most populated county wins were in El Paso County, where Colorado Springs is located, and Weld County, home to Greeley.

Colorado served as the tipping-point state for Obama's overall victory in the presidential election - that is, the first state to give a candidate their 270th electoral vote when all states are arranged by their margins of victory.